Belt dressing



Patented May 8, 1934 BELT DRESSING James A. Webb, Buffalo, N. Y.,assignor to J. A. Webb Belting 00., 1110., Buffalo, N. Y.

No Drawing. Application February 5, 1932, Serial No. 591,237

6 Claims.

My invention relates to belt dressings, and it has particular referenceto a composition of matter, and a method of making the same, providingan improved material for treating belting to increase the longevity anddriving power thereof.

Transmission belts are customarily made of leather, canvas or othervegetable base fabric, or fabric impregnated with rubber, and, whilenew, often fail to deliver the required amount of horsepower, or, duringservice, may become dry or harsh, due to the absence of suitablelubricating material. It has heretofore been proposed to apply variouscompositions to condition the belt for use, or to recondition a usedbelt, and in such conditioning, the objects have been-to soften thebelt, so that it would not crack or break, and also to enhance itsadhesive qualities against the pulley or driving wheel with which itcontacts. Various oils, resinous substances, and the like, haveheretofore been used for such purpose.

In considering the matter of providing an adequate belt dressing, I havediscovered that a dressing which is applicable to one type of belting isnot equally applicable to another. A dressing suitable for a leatherbelt might not possess enough pulling power for a rubber or rubberizedbelt, while again, a dressing suitable for a leather belt might detractfrom, rather than add to, the adhesive qualities of a canvas belt. Thefactors desired are, therefore, a composition which serves to lubricatethe fibers of the material of which the belt is made, without causingthem to separate or disintegrate, and a composition which also impartsto the belt surface an enhanced adhesiveness to the pulley or otherdriving wheel. Compositions which have little or no penetrating power,and which are composed of solid or thick substances, tend to build up onthe belt surface, and thus fail to supply the desired degree of internallubrication, while some purely oleaginous substances may fail as beltdressings because of lack of adhesion imparting qualities.

In a prior patent, No. 1,765,553, I have pointed out that blown tallow,either when used alone or admixed with other ingredients, is asatisfactory belt dressing, particularly for leather belting, and thatsuch material may be used without allowance for time consumed to breakin the belt, or that time after the application of the dressing duringwhich the adhesive and pulling properties of the belt are decreased,rather than increased. I have further discovered that, while suchmaterial may be applied to rubber and canvas belting, more efficaciousresults for'these materials are obtained by using a belt dressing inwhich the major constituent is a blown vegetable oil, and, moreparticularly, oils of the class known as semi-drying oils, of whichcottonseed oil is exemplary.

Without desiring to commit my invention to the ultimate exhaustivedemonstration of my present views, I may state that my observations areto the effect that the vegetable oils are more specific in theirbeneficial effects to belts which contain appreciable quantities ofvegetable fiber. The animal fats, such as tallow and neats-foot oil, arelikewise more applicable to leather belts. I have found that there is agreater nourishing quality and penetrating value for vegetable fiberbelting in an oil such as cottonseed oil, whereby adequate lubricationis obtained with a minimum of material, and, to supply the desiredadhesion imparting qualities, I subject the oil to an air blowingprocess, and also may resort to the compounding of the blown oil withother ingredients.

The blowing process is readily conducted by placing a quantity of theoil in a vat and blowing clean air therethrough for a suitable length oftime. The blowing process may be conducted more satisfactorily atelevated temperatures, and it should be continued until the viscosity ofthe oil has reached a predetermined point. In the case of the vegetablesemi-drying oils, for example, the blowing process may be controlled bymeasuring the iodine value, but it is usually sufficient to sample theoil from time to time, and determine the viscosity.

For cottonseed oil, which is an economical material and one readilysusceptible of treatment, I heat the oil to a temperature of about 250F., and continue the blowing process until the viscosity has beenincreased from its initial value (about one or two minutes Saybolt) to avalue between say ten and forty-five minutes Saybolt. I find that a lessdegree of blowing is beneficial, but the full value of the process isnot realized, while if the viscosity is materially increased above therange given, for example, to fifty-six minutes, the oil is too viscousfor general application. Other vegetable oils, such as corn oil, may beused in lieu of the cottonseed oil, or a mixture of oils may, betreated, but I find that cottonseed oil alone, treated as described,produces a highly practical product.

To the treated oil may be added other sub- 1 stances, such as tar,asphaltic bodies, pitch, rosin, or gums, in accordance with thecompounding practices known in the art, but to much less extent thanheretofore deemed necessary to effect the results desired. It is notnecessary, when us- 1'10 ing blown oil, 'to add the relatively highpercentages of thue substances which have hereto--forebeenused,andtheuseofsmallamounts only has the added advantage ofavoiding too much stickiness in the completed I find that blownvegetable oils, such as the blown cottonseed 011 just referred t may beapplied as a belt dressing to various types of belting with goodresults. It may be applied to rubberor rubberized fabric belting, forexample, without danger of softening the rubber in a destructive manner.By this discovery, I have overcome one of the outstanding objections todressings for rubber belts. In the caseof rubber belts, the blowncottonseed oil immediately imparts enhanced adhesive properties to thebelting, whereas, with other materials, a considerable time solid shouldbe employed, and hence it will be seen that the viscoflty isadvantageously brought within the limits herein set forth. For thisapplication, it is better to form a mixed composition than to omit theadded material and increase the viscosity of the oil above the limitsgiven, for otherwise the oil will be lacking in penetrative properties,and the desired virtues of the s,-lubrication, traction, and absence ofdeterioration, may not be obtained in optimum ratios.

It will be seen, therefore, that my invention contemplates the provisionof a belt dressing which contains no ingredients harmful to the belting,which serves to lubricate the belt and increase immediately itstraction, and which dressing is made essentially of blown vegetableoils, particularly such semi-drying oils as cottonseed oil, so treatedas to have enhanced viscosity and withal be penetrative, admixed withother ingredients or used without such other ma- 2. The method ofdressing a belt to enhance its driving properties which comprisesapplying thereto blown cottonseed oil.

3. The method of dressing a beltto enhance its driving properties whichcomprises applying thereto blown cottonseed oil having a viscosity of.ten to forty-five minutes Saybolt.

4. The methodvof dressing a belt to enhance its driving properties whichcomprises applying thereto blown semi-drying vegetable oil having aviscoscity of ten to forty-five minutes Saybolt.

5. The method of dressing a belt to enhance its driving properties whichcomprises applying thereto a composition of blown semi-drying vegetableoil and a substance of the class consisting of tar, asphalt, rosin,pitch, and gum.

6. The method of dressing a belt to enhance its driving properties whichcomprises applying thereto a composition of blown cottonseed oil and asubstance of the class consisting of tar, asphalt, rosin, pitch, andgum.

JALdESAWEBB.

